US5238738A
Expired / Lapsed
US
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Polymeric minus filter
Assignee: 3M Co
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Filing: 1991-10-29
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Granted: 1993-08-24
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Expires: 2011-10-29
Abstract
Abstract A polymeric minus filter for an incident electromagnetic spectral band comprises at least one polymeric interference stack tuned to a predetermined design wavelength centered around λ 0 , wherein λ 0 is in the range of 300 nm to 2000 nm, said filter comprises an optically transparent substrate and having deposited thereon at ambient temperatures (20° to 23° C.) a multiplicity of pairs of polymeric thin interference layers plus one final polymeric layer having index of refraction n 2 , each pair of interference layers having a total optical thickness equal to 1/2 wavelength of λ 0 , the members of each pair having refractive indices n 1 and n 2 , respectively, wherein the layer having refractive index n 2 is directly superimposed upon said substrate having refractive index n s and wherein n s is approximately equal to n 1 , and wherein n 2 <n 1 .
Inventors
- 👤 Robert H. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:45
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/285; G02B5/287; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/26; Y10T428/261; Y10T428/31504; Y10T428/31507; Y10T428/31533; Y10T428/31652; Y10T428/31663; Y10T428/31678; Y10T428/31692; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31931; Y10T428/31935
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
148 words
A polymeric minus filter for an incident electromagnetic spectral band comprising at least one polymeric interference stack tuned to a predetermined design wavelength centered around λ 0 , wherein λ 0 is in the range of 300 nm to 2000 nm, said filter comprising an optically transparent substrate and having deposited thereon a multiplicity of pairs of polymeric thin interference layers plus one final polymeric thin interference layer having index of refraction n 2 , each pair of interference layers having a total optical thickness equal to 1/2 wavelength of λ 0 , the members of each pair having refractive indices n 1 and n 2 , respectively, wherein the layer having refractive index n 2 is directly superimposed upon said substrate having refractive index n s and wherein n s is approximately equal to n 1 , and wherein n 2 is less than n 1 .
Claim 2
Dependent Claim
148 words
A polymeric minus filter for an incident electromagnetic spectral band comprising at least one polymeric interference stack tuned to a predetermined design wavelength centered around λ 0 , wherein λ 0 is in the range of 300 nm to 2000 nm, said filter comprising an optically transparent substrate and having deposited thereon a multiplicity of pairs of polymeric thin interference layers plus one final polymeric thin interference layer having index of refraction n 2 , each pair of interference layers having a total optical thickness equal to 1/2 wavelength of λ 0 , the members of each pair having refractive indices n 1 and n 2 , respectively, wherein the layer having refractive index n 2 is directly superimposed upon said substrate having refractive index n s and wherein n s is approximately equal to n 1 , and wherein n 2 is less than n 1 .
Claim 3
Dependent Claim
12 words
The minus filter according to claim 1 wherein said substrate is transparent.
Claim 4
Dependent Claim
13 words
The minus filter according to claim 1 wherein said substrate is partially absorbing.
Claim 5
Dependent Claim
24 words
The filter according to claim 1 wherein said substrate is selected from the group consisting of polycarbonate, polystyrene, polyacrylate, polyaryl sulfone, polyester, and polysulfone.
Claim 6
Dependent Claim
13 words
The filter according to claim 4 wherein said substrate is polycarbonate or polystyrene.
Claim 7
Dependent Claim
33 words
The filter according to claim 1 wherein said polymeric thin interference layer having refractive index n 1 , is selected from the group consisting of plasma polymerized polystyrene, hexamethyl disiloxane, and polymethyl methacrylate.
Claim 8
Dependent Claim
32 words
The filter according to claim 1 wherein said polymeric thin interference layer having refractive index n 2 is selected from the group consisting of plasma polymerized polymethyl methacrylate, polystyrene, and hexamethyl disiloxane.
Claim 9
Dependent Claim
22 words
The filter according to claim 1 having a number of interleaved polymeric stacks equal to the number of rejection bands of wavelengths.
Claim 10
Dependent Claim
23 words
The filter according to claim 8 wherein each of said stacks has in the range of 25 to 2500 pairs of interference layers.
Claim 11
Dependent Claim
43 words
The filter according to claim 1 wherein said substrate is polycarbonate, said interference layer having index of refraction n 1 is plasma polymerized hexamethyl disiloxane, and said interference layer having index of refraction n 2 is polymethyl methacrylate or plasma polymerized hexamethyl disiloxane.
Claim 12
Dependent Claim
16 words
The filter according to claim 1 wherein λ 0 is a wavelength in the visible range.
Claim 13
Dependent Claim
17 words
The filter according to claim 1 wherein λ 0 is a wavelength in the near infrared range.
Claim 14
Dependent Claim
11 words
The filter according to claim 1 wherein said substrate is polycarbonate.
Claim 15
Dependent Claim
21 words
The filter according to claim 1 wherein said interference layer having index of refraction n 2 is plasma polymerized hexamethyl disiloxane.
Claim 16
Dependent Claim
20 words
The filter according to claim 1 wherein said interference layer having index of refraction n 1 is polymerized hexamethyl disiloxane.
Claim 17
Dependent Claim
18 words
The film according to claim 10 wherein said interference layers are deposited on said substrate at ambient temperatures.
Claim 18
Independent Claim
135 words
A method for preparing a minus filter comprising a stack of organic layers for rejecting an incident electromagnetic spectral band comprising the step of depositing on an optically transparent substrate having refractive index n s a multiplicity of pairs of plasma polymerized organic interference layers having refractive indices n 1 and n 2 , n 2 being lower than n 1 , wherein a layer having refractive index n 2 is directly superimposed upon the substrate, and n s is approximately equal to n 1 , and depositing a final plasma polymerized organic layer having refractive index n 2 , said layers and substrate providing a polymeric interference stack which is tuned to a predetermined design wavelength centered around λ 0 , wherein λ 0 is in the range of 300 nm to 2000 nm.
Claim 19
Independent Claim
135 words
A method for preparing a minus filter comprising a stack of organic layers for rejecting an incident electromagnetic spectral band comprising the step of depositing on an optically transparent substrate having refractive index n s a multiplicity of pairs of plasma polymerized organic interference layers having refractive indices n 1 and n 2 , n 2 being lower than n 1 , wherein a layer having refractive index n 2 is directly superimposed upon the substrate, and n s is approximately equal to n 1 , and depositing a final plasma polymerized organic layer having refractive index n 2 , said layers and substrate providing a polymeric interference stack which is tuned to a predetermined design wavelength centered around λ 0 , wherein λ 0 is in the range of 300 nm to 2000 nm.
Claim 20
Dependent Claim
28 words
A method for rejecting multiple bands of incident electromagnetic radiation comprising a composite of multistacks, each of said stacks being prepared by the method according to claim 17.
Claim 21
Dependent Claim
50 words
A method of protecting a radiation sensitive object from at least one selected wavelength of unwanted electromagnetic radiation comprising the step of: providing the minus filter according to claim 1 which is positioned so as to prevent said selected wavelength of electromagnetic radiation from reaching said object to be protected.
Claim 22
Dependent Claim
20 words
The polymeric minus filter according to claim 1 wherein said polymeric thin interference layers are vacuum deposited by plasma polymerization.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-23 | 1997-02-22 | 1997-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-23 | 2001-02-22 | 2001-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-23 | 2005-02-22 | 2005-08-24 | $7700.00 | Window Closed / Lapsed |